title: Not innocent: verdict from ab initio multiconfigurational second-order perturbation theory on the electronic structure of chloroiron corrole.
abstract: From a suitably broad perspective, transition metal corroles may be viewed as stable, synthetic analogues of high-valent heme protein intermediates such as compounds I and II. Against this backdrop, the electronic structure of chloroiron corrole has provoked a lively debate in recent years. Thus, whereas NMR spectroscopy and DFT calculations suggest an S = 3/2 Fe(III) corrole (*2-) radical description, certain researchers have favored an Fe(IV) formulation. These two descriptions are indistinguishable as far as DFT calculations are concerned. Ab initio CASSCF/CASPT2 calculations provide unambiguous support for the former description. In addition, they rule out any Fe(IV) state, whether high- or low-spin, within 1.5 eV of the ground state.
authors.affiliation: Department of Theoretical Chemistry, Chemical Center, University of Lund, P.O. Box 124, S-221 00 Lund, Sweden.
authors.forename: Björn O
authors.initials: BO
authors.lastname: Roos
authors.forename: Valera
authors.initials: V
authors.lastname: Veryazov
authors.forename: Jeanet
authors.initials: J
authors.lastname: Conradie
authors.forename: Peter R
authors.initials: PR
authors.lastname: Taylor
authors.forename: Abhik
authors.initials: A
authors.lastname: Ghosh
mesh_terms: D004583:Electrons; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D011166:Porphyrins / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D011166:Porphyrins